1. Field of the Invention
This invention relates to an image generation device and an information storage medium for generating an image that enables a player to use a shooting device to shoot at a target object within an object space.
2. Description of Related Art
Image generation devices have been developed and implemented in the art, to enable a player to use a shooting device such as a handgun-shaped controller to shoot at a target object. When a player 520 pulls a trigger of a handgun-shaped controller 522 of such an image generation device, as shown in FIG. 1A, a two-dimensional position on a display screen 512 that is indicated by the handgun-shaped controller 522 is optically detected. If the thus-detected two-dimensional position matches the position of a two-dimensional target object that is displayed on the screen, this is determined to be a hit; if it does not match, this is determined to be a miss. This image generation device makes it possible for a player to enjoy the virtual experience of target-shooting or gun-fighting without using a real firearm, so it is highly popular as a game.
When a plurality of players play on an image generation device of this type (with a multi-player game), first and second players 520-1 and 520-2 both use the same display screen 512 in common, as shown in FIG. 1B. In other words, the viewpoints of the first and second players 520-1 and 520-2 within the object space are the same, and the first and second players 520-1 and 520-2 shoot by aiming at a target object seen from the same viewpoint.
With the method shown in FIG. 1B, however, the viewpoints of the first and second players 520-1 and 520-2 within the object space are the same, unlike in the real world. This makes it impossible to further heighten the players"" experience of a virtual reality.
In addition, since the images seen by the first and second players 520-1 and 520-2 are always the same, it is also impossible to increase the dramatic effect of the game any further.
This invention was devised in the light of the above described technical concerns and has as an objective thereof the provision of an image generation device and information storage medium that make it possible to heighten the virtual realism and the dramatic effect of the game in an efficient manner.
In order to address the above technical concerns, this invention relates to an image generation device for generating an image that enables a player to use a shooting device to shoot at at least one target object within an object space. This image generation device comprises: means for performing processing for setting a plurality of objects, including a target object, within the object space; means for performing a hit check between a shot from a first player and a target object; means for performing a hit check between a shot from a second player and a target object; means for controlling a first viewpoint for the first player; means for controlling a second viewpoint for the second player; means for generating an image as seen from the first viewpoint within the object space and outputting the generated image to a first display screen for the first player; and means for generating an image as seen from the second viewpoint within the object space and outputting the generated image to a second display screen for the second player.
With this aspect of this invention, the first player can enjoy shooting at target objects while watching an image as seen from a first viewpoint in the object space and the second player can also enjoy shooting at target objects while watching an image as seen from a second viewpoint in the object space. This enables a huge increase in the players"" feeling of virtual realism and the dramatic effect of the game, unlike in the prior-art example in which the viewpoints of the first and second players are the same. It also makes it possible to prevent the displayed images from becoming too uniform, further increasing the degree of variety of the images. It is also possible to create differences in the virtual realities experienced by the first and second players.
Note that the scope of this invention also covers an implementation in which each of the hit check, viewpoint control, and image generation is performed by a single means instead two means each.
The first and second viewpoints may be controlled in such a manner that the first viewpoint moves along a given first movement path and the second viewpoint moves along a given second movement path. This independent control of the first and second viewpoints makes it possible to provide different images to be seen by the first and second players, which increases the dramatic effect of the game.
The first movement path of the first viewpoint and the second movement path of the second viewpoint may be made to diverge when a given circumstance occurs. Such a configuration makes it possible to set scenarios such as one in which the first and second players shoot at target objects from completely different places within the object space, which increases the degree of variety of images.
Character objects corresponding to each of the first and second players may be provided within the object space; and, when a given circumstance occurs, the viewpoint of one of the first and second players may be controlled in such a manner that a target object and the character object corresponding to the other of the first and second players both enter into the field of view of the viewpoint of the one of the first and second players. Such a configuration makes it possible to strengthen the sensation of playing cooperatively with another player, which increases the degree of absorption of the player in the game.
At least one of the first viewpoint, the second viewpoint, and a target object may be controlled in accordance with a difference in game results between the first and second players. Such a configuration makes it possible to generate different images and move the game forward in different ways, depending on game results that reflect the abilities of the players, which further increases the dramatic effect of the game.
When a target object that is present within the field of view as seen from one of the viewpoints of the first and second players has been destroyed but a target object that is present within the field of view as seen from the other of the viewpoints has not been destroyed, the one of the viewpoints may be controlled in such a manner that the target object that is present within the field of view as seen from the other of the viewpoints enters the field of view as seen from the one of the viewpoints. Such a configuration makes it possible to set scenarios such as one in which one player can support the other player.
When a target object that is present within the field of view as seen from one of the viewpoints of the first and second players has been destroyed, target object control may be performed in such a manner that a target object enters the field of view as seen from the one of the viewpoints. Such a configuration makes it possible to prevent the occurrence of a situation in which one player has to wait for the other player to finish playing the game.
When a game result of one of the first and second players is greater than a game result of the other of the players, one of the viewpoints may be made to proceed in advance of the other of the viewpoints. Such a configuration makes it possible to stimulate a competitive feeling between the players, which increases the players"" enthusiasm and degree of absorption in the game.
When one of the viewpoints is proceeding in advance of the other of the viewpoints, a target object may be caused to appear within the field of view of the other of the viewpoints, in a region between the one viewpoint and the other viewpoint. Such a configuration makes it possible to control the appearance of target objects in accordance with a difference between game results.
Character objects corresponding to each of the first and second players may be provided within the object space; and, when a shot from one of the first and second players has hit the character object corresponding to the other of the first and second players, an image that is output to a display screen provided for the other player may be made to change. Such a configuration makes it possible to convey to the other player that one player has mistakenly shot him.
A check may be performed to determine whether or not a shot from the first player has hit a target object, based on a first trajectory specified by the first viewpoint and a two-dimensional position on the first display screen that is indicated by a shooting device of the first player; and a check may be performed to determine whether or not a shot from the second player has hit a target object, based on a second trajectory specified by the second viewpoint and a two-dimensional position on the second display screen that is indicated by a shooting device of the second player. Such a configuration makes it possible to cause changes in the motion of a target object in accordance with the first and second trajectories and so on, which increases the realism of images.